Racket string stretcher



Mar ch 10, 1936. w. G. TOPE 2,033,264

RACKET STRING STRETCHER Filed May 8, 1933 INVENTOR Top? ATTORNEY Patented Mar. 10, 1936 UNITED STATES wer PATENT orriea 6 Claims.

This invention relates to devices for stringing tennis rackets, the principal objects of my invention and the advantages over the present devices used for the purpose being as follows:

1. The breakage of the racket frames is entirely eliminated.

2. The breakage, damage or fraying of the strings is also entirely eliminated.

3. Tighter stringing is possible.

4. Even tension on all strings is assured.

5. Warping of the frames is prevented.

6. The shape of the racket frame is under the entire control of the operator and may be adjusted to be of any desired shape.

7. The apparatus may be used by an operator with a few days instruction, after which he can do work superior to that produced by the best experienced men with other devices and methods.

A further object is to provide a device for the purpose which may be conveniently used with the standard apparatus at present employed. and which practically every repair man and factory shop possesses so that the cost of purchase is kept to the minimum.

A further object of the invention is to produce a simple and inexpensive device and yet one which will be exceedingly effective for the purpose for which it is designed.

These objects I accomplish by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and claims.

In the drawing similar characters of reference indicate corresponding parts in the several views:

Fig. 1 is a top plan view of the complete stringing apparatus as in operation.

Fig. 2 is a side elevation of the same.

Fig. 3 is an enlarged cross section of the handle clamping unit as on the line 3-3 of Fig. 2.

Referring now more particularly to the characters of reference on the drawing, the standard equipment at present used and which I employ in connection with my invention, comprises a base I of suitable character on which a standard 2 45 is mounted to support the racket frame 3 at its head end. A clamp 4 associated with the standard releasably holds the frame head against movement. Another clamping device 5 is mount- 50 ed on the base to engage the handle 6 of the racket on opposite sides near the corresponding end of the frame. This equipment constitutes all that is now provided in connection with racket stringing and its manipulation even with 5 care causes the fracturing of the frames and the breakage of the strings to be a rather frequent occurrence.

My invention to improve the method of applying the necessary tension to strings comprises a pair of blocks 1 of a fine grain and hard wood 5 adapted to directly engage the handle 6 on its opposite sides and beyond the clamp 5. This clamp now serves merely as a support for the handle to maintain the same horizontal while the strings are being applied and is-preferably mounted for transverse adjustment on the base I as indicated in Fig. 1, so that it will always maintain a transversely centralized position relative to the racket regardless of different widths of racket handles. 7

The blocks 1 are backed with metal plates 8 which are secured to said blocks by bolts 9 which are countersunk in the blocks. as shown in Fig. 3 by stove bolts 9. These blocks are adjustably connected together by longitudinally and vertically spaced pairs of bolts l9 non-turnably mounted in one plate 8 and slidably projecting through the opposite block and plate with a free fit, so that blocks maybe adjusted to non-parallel positions relative to each other if a slight taper of the handle necessitates this position. Adjustable wing nuts II. on. the bolts enable the blocks to be firmly clamped against the handle. I use wood; for the, blocks not only to prevent damage being done to the wooden handle as by scarring or indenting the same, but wood has a better grip with the wood of the handle than would otherwise be obtained. Turnable on the upper bolts l0 between the blocks are rollers I2 preferably faced with felt and which ride on top of the handle so that the clamping unit may be initially supported on the handle in the proper position.

The ends of the plate 8 beyond the handle are connected by links I3 or the like to one end of a turnbuckle M the opposite end of which engages an anchor eye l5 mounted in a fixed position on a level with the top of the standard 2. The eye may be secured separate from the base but I have here shown the same as being mounted on a post [6 upstanding from said base so as to maintain the same in unitary association with the various racket holding clamps. The diameter of the rollers is such that when they are resting on the handle the linkage and turnbuckle are horizontal, or in a plane axially of the handle. In this manner the pull on the handle and frame is direct from end to end and there is no tendency to twist or bend the racket at any point.

In operation the racket is first mounted in connection with the clamps 4 and 5 of the apparatus. 5

The longitudinal strings I! are then strung in the racket frame 3 and are tightened by hand sufiiciently to spread the frame and widen the same from normal to a certain extent, preferably not to exceed 7/16 of an inch, or to the size indicated at A in Fig. 1. After this is done, the clamping block unit is slid over the handle from its rear end and firmly tightened against the same.

The turnbuckle is then manipulated so as to place the handle and consequently the strings and frame under tension, and until the racket frame is returned to Within approximately onefourth of an inch of its normal transverse diameter. apparatus the cross strings are applied and pulled in. Since the tension on the long strings has already been taken through the stretcher, the cross strings do not have this force to overcome and an even moderate pull on each cross string is sufiicient to cause the frame to be readily pulled in or returned to its normal form and size. Then, when the racket is withdrawn from the stretcher, the tension on the racket frame due to said stretcher is released and the long strings being free to exert a spreading tendency on the.

frame causes an additional tension to be placed on the cross strings and the tension of all the strings, both longitudinal and crosswise, is equalized.

From the foregoing description it will be readily seen that I have produced such a device as substantially fulfills the objects of the invention as set forth herein.

While this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention, as definedby the appended claims.

Having thus described my invention what I claim as new and useful and desire to secure by Letters Patent is:

V 1. A racket string stretcher comprising, in combination with a fixed clamp to engage the top and bottom surfaces of the racket frame at its head end, a clamping unit for engagement with the handle of the racket while the frame thereof is engaged by said fixed clamp, and means applied to said unit at the end furthest from the- While the racket frame is still in the clamp to pull the same lengthwise of said handle and away from said fixed clamp.

2. A racket string stretcher comprising in combination with a fixed clamp to engage the top and bottom surfaces of the racket frame at its head end, a clamping unit for engagement with the handle of the racket, a fixed anchor member beyond said unit in the direction opposite said clamp, and a turnbuckle between and connected to said anchor member and clamping unit.

3. A device to apply a pulling pressure to a racket handle including a clamping unit comprising spaced clamping blocks to engage the handle on opposite sides and for a considerable portion of the length thereof, transversely and longitudinally spaced pairs of bolts adjustably connecting the blocks, a turnbuckle connected at one end to the end of the unit nearest the end of the handle, and an anchor member for the opposite end of the turnbuckle.

4. A device as in claim 3, in which one longitudinal pair of bolts carry rollers to ride on the-upper surface of the handle to initially position and support the unit on the handle, and

arranged relative to the point of connection of the turnbuckle with the blocks so that when said rollers are engaged with a handle, said point of connection is axially alined with the handle.

5. A device to apply a pulling pressure to a racket handle including a clamping unit comprising spaced relatively long clamping blocks of wood to engage the handle on opposite sides, rigid metal backings on which said blocks are mounted, adjustable connection means between the blocks, and pulling means applied to said initially position and support the unit on the handle.

. W'ILBUR. G. TOPE. 

